Method of treating wood surfaces for photographic reproduction thereof



Patented Aug. 4, 1936 p UNITED STATES PA'lE NT OFFICE METHOD or TREATING woon summons ron PHOTOGRAPHIC naraonucrron THEREOF Lawrence J. Pearson, Wyncote, Pa., assignor to Philco Radio 8; Television Corporation, Philadelphia, Pa, a corporation of Delaware No Drawing. Application April 4, 1936, Serial-No. 72,836 v Claims. (Cl. 41-41) y 10 stone surface to form a positive reproduction of the image on that surface. If desired, several different positive plates maybe formed, each having thereon only that part of the image correspending to a certain color or colors in the original image. By printing with different colors applied to the several plates, a colored image of the original object may be obtained on a transfer paper, and this image may be-transferred to another object to give such object a desired appearance or finish. The image may be transferred to the surfaces of various objects, such as objects made of wood, asbestos, metal, pottery, china, or

the like. In this manner, a large number of objects may be given a desired appearance. For

example, articles of furniture may be subjected to the transfer process to give them a desired appearance.

By the present invention, a wooden object or surface may be. treated in a manner to bring out or emphasizecertain desirable characteristics to prepare the wooden object or surface for photographing, the object being to improve the reproduction obtainable by the transfer process above mentioned. More specifically, the invention provides a suitable method of treatment for a' wood surface by means of which the grain and other characteristics of the wood surface may be reproduced more clearly and by which a photograph suitable fortransfer purposes may be obtained.

.Varioustypes of wood may be treated by the treatment of any wood of relatively coarse grain structure suitable for the transfer-process.

The invention comprises essentially the folll lowlngml fl lttreatingthewoodwithasub stance capable of etching the grain and freeing the pores of sap or other matter, bleaching the wood thus treated, coating the bleachedwood with a colorless impermeable substance, and

finally applying a colored filler to fill the pores "5' and grain depressions and to establish a contrast between the filled pores and the remainder of the wood surface. These successive steps will now bedescribed in detail with reference to a preferred embodiment of the invention. 10 As stated above, the first step in the process is the treatment of the wooden object or surface with a substance capable of freeing the grain depressions and pores of sap and other matter. This step prepares the wood for the subsequent 15 steps of the process. I have found that a caustic solution is well adapted for this purpose. Preferably, a 10% (by weight) aqueous solution of sodium hydroxide (NaOHl is employed, although "the strength of the solution mayvary in a range from approximately 8% to approximately 12%.

In general, if the strength of the solution is less than 8%, the desired cleansing action is not efiiciently performed, while, on the other hand, if the strength of the solutionis greater than 12%, the solution is so strong that it tends to burn or carbonize the wood, which, of course, is undesirable. It will be understood that any alkali solution having a s rength equivalent to that above mentioned may be used.

so Following the treatment with the cleansing solution, the wood is washed in cold water until it is substantially free of the solution and it is then allowed to dry. For best results, the wood should be thoroughly dried before it is treated 35 'further.

The next step in the process the bleaching step. The purpose of this treatment is to lighten the color of the wood so that a strong contrast may be established between the wood and the 49 filler which is subsequently applied to the cleansed pores of the wood structure. By providing this strong contrast, the wood is rendered more suitable for the photographic and transfer processes,

as above mentioned. Any bleaching agent capable 5 of bleaching the wood may be employed in this treatment, but I prefer to use a strong aqueous solution 'of hydrogen peroxide (H202). Preferably, a 30% solution of hydrogen peroxideis employed and is allowed to remain on the surface 50 of the wood for approximately four or five minutes. The peroxide solution isthen removed and the wood is allowed to dry almost P te y.-

I after which it is treatedwith a strong aqueous solution of (NHiOlEi) which serves to wire brush or like implement may be used to brush the surface of the wood after sanding.

The next step in the process is the application of a substantially colorless coating which is impermeable or incompatible with respect to a wood filler and which serves to prevent the wood from absorbing or taking up the filler to be applied later. In this manner, only the pores and grain depressions of the wood are filled with the filler in the final step. Preferably, a light coat of bleached white shellacmay be employed to coat bleached wood. The coating may be applied in any suitable manner, for example, by means oi; a brush, by spraying, or in any other conventional manner. The shellac preferably comprises a solution containing approximately 10% gum in an ethyl alcohol solvent. It will be understood, of course, that any unpigmented colorless finishing material, such as gloss lacquer or other shellac substitutes, may be used in this treatment, provided the maximum solid content is not much greater than 10%.

The final step of the process is the application of a suitable wood filler which, because of the previous coating treatment, serves only to fill the pores and grain depressions of the wood and does Percent Powdered gypsum 21 Crystalline silex 300 mesh. 35 Magnesium silicate 14 Lead oxide .7 Pigmented coloring matter 11.3

8% raw sienna 3.3% burnt sienna Filler vehicle 18 This filler has a reddish brown color which is suitable for the photographic process employed in the transfer or reproduction. The filler vehicle may comprise china wood oil, gloss oil varnish, and a drier. The filler may be conveniently dissolved in V. M. P. (Varnish Makers and Painters) naphtha using approximately 12 lbs. of filler per gallon of naphtha. The wood may be given one coat of filler and allowed to dry. It may then be sanded and given a second coat and then allowed to dry. Following the second coat, the wood may again be lightly'sanded.

When completed, the surface of the wood is characterized in that the high lights or hard portion of the wood will have a very light color due to the bleaching process, whereas the grain of the wood, which has been cleaned out and filledwith a colored filler, will appear in strong contrast. The general surface of the wood will appear more or less dull and will not be light-reflecting to any great extent. As will be understood, this lack of a shiny finish in combination with the strong contrast between the grain of the wood and the hard portions of the wood are 6 of material assistance in obtaining a photograph of the panel which will clearly show up or indicate the grain structure.

While certain preferred substances have been indicated above, the invention is not thus liml0 ited but comprises essentially the four steps as described regardless of the specific materials used in any of the steps. Various changes and modifications are possible without departing from the scope of the invention, provided the essential steps 15 are adhered to.

I claim:

1. A method of treating wood, which comprises treating the wood with a substance capable of freeing the pores and grain depressions of sap 20 or other matter, bleaching the wood thus treated, coating the wood with a substantially colorless filler-impermeable substance, and applying a colored filler to the coated wood so as to fill only the pores and grain depressions of the wood, 25 whereby photographic reproduction of the appearance of the grain of the wood is facilitated.

2. A method of treating wood, which comprises treating the wood with a caustic solution of desired strength to etch the grain of the wood and 30 free the pores thereof of sap or other matter, bleaching the wood thus treated, coating the wood with a substantially colorless filler-impermeable substance, and applying a colored filler to the coated wood so as to fill only the pores and 35 grain depressions of the wood, whereby photographic reproduction of the appearance of the grain of the wood is facilitated.

3. A method of treating wood, which comprises treating the wood with a caustic solution of desired strength to etch the grain of the wood and free the pores thereof of sap or other matter, washing and drying the wood to remove said solution, bleaching the wood thus treated, coating the wood with a substantially colorless fillerimpermeable substance, and applying a colored filler to the coated wood so as to fill only the pores and grain depressions of the wood, whereby photographic reproduction of the appearance of the grain of the wood is facilitated.

4. A method of treating wood, which comprises treating the wood with an 8% to 12% solution of sodium hydroxide to etch the grain of the wood and free the pores thereof of sap or other matter, bleaching the wood thus treated, coating the wood with a substantially colorless filler-impermeable substance, and applying a colored filler t0 the coated wood so as to fill only the pores and grain depressions or" the wood, whereby photographic reproduction of the appearance of the grain of 0 the wood is facilitated.

5. A method of treating wood, which comprises treating the wood with a 10% solution of sodium hydroxide to etch the grain of the wood and free the pores thereof of sap or other matter, bleach- 65 ing the wood with a 30% solution of hydrogen peroxide, coating the wood with a substantially colorless filler-impermeable substance, and applying a colored filler to the coated wood so as to fill only the pores and grain depressions of the wood, whereby photographic reproduction of the appearance of the grain of the wood is facilitated.

LAWRENCE J. PEARSON. 

